Once
again the report on the annual meeting of the American College of Sports
Medicine, this year in Indianapolis, May 28 to June 1, is a joint effort by
David Pyne and Will Hopkins. David attended the
meeting and has provided first-hand accounts of keynote and other featured
presentations, none of which have abstracts. Will did not attend the meeting
but has summarized the abstracts for the slide and poster sessions. The ACSM conference
site provides various links to information and
abstracts for the meeting.

Featured
Highlights

with
David Pyne

It was welcome back to Indianapolis, the
headquarters city of the American College of Sports Medicine. The annual
meeting is held here every few years and long-time attendees will recall the
2004 and 2008 meetings here. The main news in Indianapolis (and the whole US
for that matter) this week was the severe weather and tornado activity
stretching from Texas to Illinois. Thankfully it only rained overnight in
Indy and attendees were able to make full use of the walking trails around
the nearby canal and river. There was plenty on offer as usual, and the
highlights at this year’s meeting included minimalist running shoes and
running barefoot, many more sessions using the thematic poster format, and
lots of abstracts (as usual) on nutritional supplements and ergogenic aids.
The pre-conference program on the Tuesday seems to get bigger each year, the main sessions this year being Exercise is
Medicine, a Gatorade pre-conference nutrition symposium in an engaging
3-minutes/3-slides format, and a career-development forum.

The format of the thematic poster sessions
involved some initial informal viewing time and then moderator-lead
discussion over 2 h. This format obviously provides for meaningful
interaction and discussions, but I wonder how many attendees were like me: a
quick perusal of the posters then out the door before the moderated
discussions got underway.

The free wireless internet
at the convention center worked well in the lobby and foyer areas, but not in
the lecture rooms–rather inconvenient, given the abstracts were
available only online. Clearly the days of the big abstract book are
numbered, as ipads and smart phones become more
popular. Navigation down each aisle of the poster boards would also be easier
with larger signage on both sides of the boards signaling the start of a new
numbered section.

The opening session of this year’s meeting
was the JB Wolffe Lecture Exercise is
Medicinepresented
by Scott Powers. Here Powers outlined some of the newer benefits of regular
exercise, including browing of adipose tissue, reduction
in cardiac reperfusion injury, reduction in
chemotherapy for cancer. Proposed mechanisms around cardioprotection
include vascular adaptations and intrinsic changes to cardiac myocytes. Recent research is highlighting the important
role of mitochondrial antioxidants, particularly superoxide dismutase. While
the focus here was on exercise in (clinical) medicine, this work also sheds
light on oxidative stress and adaptive responses in athletes.

Of interest to readers of this journal was
the session on ClinicalDecisionMaking
by Evert Verhagen, Steven Stovitz
and Ian Shrier. Like a lot of sessions at the
Annual Meeting, this session had more of a clinical focus on health, activity
and illness rather than sports performance. Verhagen,
an epidemiologist, outlined some emerging approaches quantifying benefit and
harm to inform clinical decision making, and misconceptions around use of
p-values. He outlined different forms of ‘costs’ including
side effects of interventions, relative costs, logistics and comfort in
prescribing interventions. Stovitz discussed the
number-needed-to-treat approach and the subtleties of various kinds of risk. Shrier detailed his published work on return-to-play decisions
involving models of shared decision making with clinicians, scientists,
coaches and the patient/athlete.

A symposium on Critical Power: Cardiovascular and
Metabolic Determinantshighlighted
the importance of oxygen kinetics and critical power in regulating exercise
and sports performance. Andy Jones outlined some practical applications of
manipulating oxygen kinetics for enhancement of sports performance. For example
Steve Ingham and colleagues at the English Institute of Sport have shown the
benefits of prior high-intensity exercise as part of the warm-up for 800-m
track events. A priming bout of 200-m fast running at 800-m race pace can be
used approximately 15 min pre-race. This practice can reduce the slowing of
running speed in the later stages of the race and was used at the London 2012
Olympics. AnniVanhatalo
summarized her research on changes in VO2 kinetics and the
power-time relationship in individual sports such as cycling and running.
Both the critical power or velocity and the anaerobic work done above the
critical power or velocity contribute to high-intensity performance. Philip Skiba presented an interesting approach to estimating
anaerobic capacity during intermittent high-intensity exercise.

There was a good crowd in attendance at a
symposium on Synthesizing Resistance Training Research featuring
Brent Alvar, Mike Stone and John McCarthy. Alvar outlined some of the history of ACSM Position
Stands on resistance training released in 1998, 2002, and 2009-11. The
discipline of resistance training (or S&C–strength and conditioning) is gaining
more academic credence with release of more scholarly research and some
meta-analyses. Stone provided some practical examples of challenges for
practitioners from his long involvement with elite athletes. McCarthy
outlined current thinking on combining resistance with endurance training. He
argued the key factor was the frequency of concurrent training–too many
combined sessions can cause problems. Mechanisms of interference include
reduced hypertrophy, reduced muscle glycogen and myofibrillar
protein concentration, increased conversion of fast- to slow-twitch muscle
fibers, interference to neural adaptations, and altered catabolic/anabolic
hormone concentrations.

Genetics is now everywhere in medicine and
sports science, and the latest word is that it will
be possible for any individual to have their full genome sequenced for
~$1,000 within the next two years. James Skinner gave an informative tutorial
session on Genetics for Professionals looking
back at the high profile HERITAGE study conducted from 1992-2004. From a
sports performance perspective the key issue of how individuals respond
differently to various training interventions can be investigated on a genetics basis. Skinner summarized his view that elite
athlete performance (phenotype) is influenced by a well-structured training
program and underlying genetic endowment (genotype). The hunt is on for the
genes determining responders, non-responders, and adverse responders to
training.

The genetic theme also featured strongly
in a session on the Human Microbiome and Sports Performance
presented by Larry Armstrong and Carol Torgan. The
Human Microbiome Project involved 242 subjects and yielded some fascinating
insights: there are approximately 10 times more microbes than cells, representing
1-3% of body mass, mainly in the gut. Heat stroke in athletes is due mainly
to release of lipopolysaccharide from gram-negative bacteria in the gut
producing endotoxemia, which causes failure of
major organs. Factors influencing the microbiome include diet, hygiene,
antibiotic use, the environment and physical factors related to exercise,
such as altitude, heat and humidity, and over exertion. Future work will
investigate the utility of bacterial biomarkers for identifying disease risk,
overtraining, fatigue status, and predisposition to heat illness. It is
possible this work might evolve to an athlete microbiological passport.

Altitude training always features strongly
at the ACSM. This year Jerome Dempsey gave a provocative lecture entitled Humans in
Hypoxia–a Conspiracy of Maladaptation.His
thesis was that the research and sport community often only see the benefits
of altitude training and ignore the costs, including sleep apnea,
hypertension, peripheral vasodilatation limiting oxygen delivery to the brain
and insulin resistance, all of which could negate positive physiological
effects on performance.

Fatigue from the single muscle fiber to
exercise performance was discussed in a symposium on New Insights
into Skeletal Muscle Fatigue.
Bruno Grassi neatly summarized research showing
that fatigue in muscle is associated with increased fiber recruitment oxygen
uptake. When additional fibers cannot be recruited and extra oxygen cannot be
delivered, there is a reduction in force/power. Stephen Bailey reviewed the relevant
research on nitrate supplementation showing that 2 x 70 ml shots of beetroot
juice taken 2.5 h pre-exercise can yield enhancements of 0.4% in (individual)
exercise performance and 4.2% in YoYo intermittent
recovery test (for team sports). More work is need on elite athletes. Our
understanding of the mechanistic basis of performance enhancement continues
to evolve from both human and animal studies. At present it appears that
nitrate could work via mitochondrial function, regulation of excitation-contraction
coupling, vascular control, and delivery of glucose.

The always impressive Randy Wilbur from
the US Olympic Training Center chaired a current issue on Overtraining:
Research and Recommendations for Strength, Endurance and Team Sports.
Mike Stone used a series of case studies to highlight some of challenges and
solutions in managing strength and power athletes. Long term development of
younger athletes should follow the sequence of coordination training, power
then maximal strength. Research in strength and power training is complicated
by limited sample size and the fact that training is rarely in isolation of
other factors. Preservation of ecological validity in strength research is
critical which unfortunately limits the application of studies of lower level
collegiate athletes. The long-held paradigm of the testosterone/cortisol
ratio remains interesting but not conclusive in monitoring training
responses. Bill Sands promoted the benefits of using a sports-specific
clinical/practical approach for athlete assessment rather than traditional research
designs and statistical significance in his talk on 20 y experience with
elite athletes, primarily US gymnasts. Wilber considered that underperformance is a much less
threatening term for coaches and athletes than overtraining. His traffic light analogy for managing training
loads, adaptations and underperformance would be understandable by every
coach. A three-step process was suggested for an underperforming athlete: a
comprehensive evaluation possibly including a blood test, health screen,
nutrition review, functional movement screen, and biomechanical evaluation;
then modification of training back towards an active training phase; and
finally a conservative progressive return to full training and competition.

Finally, Louise Burke from the Australian
Institute of Sport gave a very impressive president’s lecture on Sports
Nutrition–Lessons from the Coalface
to wrap up the meeting. Her key messages centered on the idea that research
is important but the rules of engagement in sports performance are different
to other non-sport research programs. Observational research designs and
issues on ecological validity prevail in many cases over a more traditional
randomized controlled approach. Burke contended that the athletes often know
more than we do about the effects (positive and negative) of various dietary
practices and nutritional interventions. Sports nutrition is a complex mosaic
of factors and should not be reduced to a black and white (right or wrong;
significant or non-significant) basis. Burke highlighted recent controversies
on sports drinks and the benefits or otherwise of nutritional supplements
that have adverse media exposure. Event nutrition is about finding the sweet
spot for athletes by employing an individualized plan customized to the
training or competition setting. She also reminded the audience that athletes
have a brain as well as muscles and a stomach. Elegant mouth-rinse studies
are yielding useful insights on the way body copes with variations in
carbohydrate availability and temperature among other exercise challenges.

Noteworthy
Abstracts

with
Will Hopkins

Having
just taken more than a full week to review the ECSS conference, I was both
relieved and disappointed to get through this report in about three full
days. Although there were more abstracts in total than at ECSS (3049 vs 2452), far fewer were relevant to my focus on athletic
performance, as you can see from the length of the two reports. ACSM is now
ACEM: the American College of Exercise (is) Medicine.

Magnitude-based
inference got a mention in six abstracts and reached the exalted status of
acronym (MBI) in one of them, but most researchers still think that p<0.05
and p>0.05 are all ye know on earth and all ye need to know. Other complaints:
sample sizes seem to be even smaller than last year, non-significance in
grossly underpowered studies is still being misinterpreted as no effect, author-defined
abbreviations are still rampant, and too many badly formatted or badly
written abstracts are getting past the sponsoring fellows of the College and
the review committee.

The
highest point in the abstract for me was a thematic poster session on training strategies and performance
[2256-2263], which had the highest concentration of high-quality studies
relevant to athletic performance that I have seen in any conference. These
studies merited a slide session.

Access the
conference abstracts via this link, which downloads the entire conference
proceedings as a PDF (21 MB). Use the advanced search form (Ctrl-Shift-F) to
find abstracts featured in this report via the number in brackets […]. You
will get several hits, but you can quickly home in on the right one. The
abstracts are also freely available in the May
supplement of Medicine and Science in Sports and Exercise, but the
efficient way of searching for individual abstracts via the search form there
no longer works.

Acute Effects

The
developers claim that prior electricalmuscle stimulation with the Compex "potentiates" performance, and if the
authors have the effects the right way around, there was indeed the
possibility of a 2.2% enhancement of a vertical jump and a 0.6% enhancement
of a 40-m dash in a crossover with 14 Division I collegiate male footballers
[2134]. But I wouldn't invest yet.

Warm-ups worked
well for performance of a golf swing in this crossover of 26 highly
proficient male golfers, but the authors didn't make it clear–and I was unable
to figure out from the litany of p values–which combination of aerobic, stretching
and specific activities was best [887].

A
review of the effects of stretching on running speed came to the conclusion
that "the majority of literature suggests that stretching has a
detrimental effect on running speed, in particular static stretching. The
results for dynamic stretching are contradictory, and there is insufficient
evidence to make a conclusion… More studies are needed on longer
distances" [2306].

So
here's one: dynamicstretching
for 15 min enhanced performance in a 5-km time trial by a large 2.2% in this
crossover in 15 male cross-country runners [698].

Staticstretching
also improved performance and efficiency of 20 cyclists in a graded (incremental?)
exercise test in this crossover study, but honestly, the effects are shown as
F statistics and with up to 5 significant digits! When will they ever learn?
[2172].

Precooling
by drinking an ice slurry had a small negative effect (0.7%) on 5-km time in
a crossover of 14 male and female distance runners [1753].

Cold-water
immersionvs sitting at room temperature
for 12 min for recovery between two 1500-m time trials in unstated
ambient conditions mimicking a semi-final and a final produced a ~1%
improvement in performance in this parallel-groups trial of 11+11 male and
female runners.
Aw, shucks, p=0.052, so it was only a "trend" [708]. In a similar
crossover study of nine endurance-trained males, the design didn't
quite simulate recovery between a semi and final, because the
researchers added an extra "300-yard shuttle run to ensure fatigue"
after the first of two 5-km runs. The second run was 10% slower with
control recovery between the runs but only 2.6% slower with 15 min of cold-water
immersion [2914]. It's surprising that such a large difference was
not significant, so maybe cold-water immersion doesn't work for everyone. The
study needs to be done with less fatigue in the second run.

Wow, put together the aerodynamic characteristics of the team-pursuit cyclists
in the lead and drafting positions, along with what looks like the
high-intensity power characteristics of the riders, and you can predict a
medal-winning pacingstrategy
in the Olympics [613].

Even
pacing
is still the best strategy in a 4000-m cycling time trial (lasting ~5.5 min) in 19
"subjects", even though efficiency declines during the time trial
[602, 603].

Eight cyclists who adapted to a "biomechanicallyadaptedshoe"
(1.5 mm of forefoot varus wedging, enhanced
longitudinal arch support and a metatarsal button) achieved 2.1% higher mean
power in a ~16-min time trial and 1.8% and 1.4% higher Wingate peak and mean
power compared with control shoes in this double-blind crossover [2855]. The
authors admitted they needed more subjects, but don't wait to try this
yourself.

Twenty-one
Division 1 female swimmersswam
1.8% slower in a 100-yd time trial when they took one breath every seven strokes
instead of the usual 2-3 [540].

Male
swimmers
had to cover less of their skin with swimsuits compared with females at the
London Olympics, with the result that the women swam relatively faster
[1763].

Compressionshirts decreased pain and
improved speed of 60 pitches in a crossover of 15 young baseballpitchers [2167].

Lower-body
compressiongarments
seem to benefit roller-skiing economy in 7 female and 7 male cross-country
skiers, but the abbreviations are too dense for me to decode
[2262].

There
has to be one delightfully impossible effect at every conference. The conclusion
in this crossover study of 20 male road cyclists was that "energetically
charged holographic
discs significantly increased power output and exercise time to
exhaustion and decreased perceived exertional pain
in enduranceathletes"
[1624]. With no plausible mechanism, this effect has to be a Type-1 error.

Correlates
of Performance

In
the Ironmantriathlon,
the faster you cycle, the slower you run, apparently, but the abstract was so
dense with confusing abbreviations that I gave up trying to figure out any
practical application [709].

Kenyansrun
more economically,
for reasons unclear [1754].

Hunters
of endurancegenes
have bagged a few more trophies [2268, 2271], but some also got away [2272].

It's interesting, but I can't
see any practical application of the finding that the resting muscle transcriptome
predicts 40-km cycling time-trial performance about as well as ventilatory
threshold does in 20 cyclists [701]. There are good reasons for
finding measures at rest or in submaximal tests that track performance, but
it's no good if you have to keep taking biopsies.

Nutrition and Drugs

If
anything, hyperhydration
had a negative effect when added to pre-cooling for endurancecycling performance in hot humid
conditions [316].

Here's
a study where they wasted 10 moderately trainedmales by assigning them to a non-training
group. The other 20 ended up in groups training hard on cycleergometers for 6 wk with beetroot juice or placebo. There were some
obvious benefits of beetroot on performance and economy, but the differences
in the huge changes in each group were not significant (thanks to the large errors
and/or individual responses) [2423]. My conclusion is that the beetroot
worked, but these athletes weren't already highly trained. The evidence is piling
up for at best no useful acute effect in such athletes (see the ECSS report), and I doubt if it will benefit training
either.

Supplementation
with sodium bicarbonate
improved 200-m rowing time by only 0.3% in a crossover with 20 male rowers
[2387]. The authors claimed a likely beneficial effect, but the smallest
important change for rowers is only 0.3% (Smith and
Hopkins, 2011), so it's only possibly
beneficial.

Ten
well-trained male rowers assigned to beta-alanine supplementation experienced
a 1.6% enhancement in 2000-m performance time compared with 10 assigned to
placebo. It's not entirely clear, but it looks like bicarbonate supplementation
enhanced the placebo group by 0.8% and the beta-alanine group by 0.3% [2126].

Caffeine
worked on various aspects of performance [1102, 1104-1107, 1112] even though
some authors claimed otherwise! A crossover study of 14 male and 12 female
Olympic-distance triathletes using actual competition times
deserves special mention: 3.7% reduction in the swim time and 1.3% in the
overall time [1109].

A
5-mg dose of melatonin
consumed 15 min before a 40-km cycle-ergometer time trial had a negligible
effect on performance compared with placebo in a crossover with 8 "subjects"
[2395]. The effect when it's consumed the night before (for sleep with a
time-zone shift) needs to be investigated.

Do
pain killers affect endurance performance? In a crossover with only six cyclists,
performance in a 10-mile time trial (~30 min) after an hour preload was 0.8%
faster with acetaminophen (paracetamol) and 4.2% slower with ibuprofen
compared with placebo [2396]. The smallest important effect on a cycling time
trial without a preload is 0.3 (Hopkins et
al., 2009) of the race-to-race variability of ~1% (Paton and
Hopkins, 2006), which comes to ~0.3%, so even if we double this threshold to
adjust for amplifying effect of the preload, paracetamol is possibly
beneficial and ibuprofen is most definitely harmful. The authors declared the
effects trivial by invoking an inappropriate effect statistic (ω2). My advice to any enduranceathletes
is to try paracetamol but don't touch ibuprofen before a race. Naturally,
discuss with your physician first.

The
blood
transcriptome (testing for genes expressed in blood) looks set to
become part of the athlete biologicalpassport for detection of abuse of erythropoietin
(EPO), judging by the outcomes in this trial of 39 endurance athletes [1757].

Here's
an example of an underpowered and poorly reported but important study from a
top research group. As a beta-agonist, salbutamol is a potential performance-enhancing
substance with a permitted upper limit of dosing to allow asthmatic athletes
to use it. So, what's the effect of dosing with 0.5× and 1× the upper limit?
The crossover with only seven runners showed 1.8% and 1.7% enhancements
respectively in a 5-km time trial compared with placebo, but "there was
no significant difference" [2420]. Did they try averaging the effects
for the two doses? What the authors concluded is unclear, because the
Conclusions section shows the Results section verbatim, but I'll bet they
took these results as evidence of no effect. Aren't they also evidence of a
substantial effect?

The
same group did a better job of reporting the effect of salbutamol on repeated sprints
in a soccer
simulation. But again, the sample size was only seven males and six females,
so the changes in each group are all over the place, and non-significance in
the Results inevitably became no effect in the Conclusion [2391]. When I
averaged the effects in both sexes and doses, I got improvements in sprint
mean time, sprint mean power (how measured in a run?) and sprint peak speed
of 0.9%, 5.7% and 0.9%. So there could be something here. My conclusion is
that someone needs to do the study with a decent sample size. Meantime don’t
be surprised if inhaler use increases amongst non-asthmatic athletes,
especially endurance athletes.

Training

Compared
with usual training, 7 wk of soccer-specific power training produced
1.4% to 2.9% more gains in performance tests and a 9.6% reduction in body fat
in a randomized trial of 8+8 Division II female soccerplayers [2257].

An
injury-prevention
program consisting of "sport-specific endurance, sprint and
jumping ability as well as strength/power of various muscle groups"
halved injury incidence in 71 professional soccer players over four seasons
[2258].

Six weeks of visiontraining produced what look like moderate
improvements (assuming the data show SEs rather than SDs) in softball
skill tests in a randomized controlled trial of 21 Division II female
collegiate softball players [2170].

Augmenting video with information about takeoff height
produced bigger gains in height in a 12-wk randomized controlled trial of 10
female and 10 male young teenage springboard divers learning new dives [2260].

Running economy was 1.2% higher with minimalistshoes
(the VibramFiveFingers)
than with usual footwear in an acute crossover, and after 14 days of adaptation
the benefit was 0.8% in 8 male and 6 female recreational athletes [684]. But
the effects were not statistically significant, so you guessed it, "the
minimal footwear did not provide an advantage". Economy was also better
by 5.8% and 2.5% in barefeet and minimalistshoes
compared with usual shoes in an acute study of eight well-trained female
distance runners [1751]. Other things being equal, a 1% improvement in
economy means a 1% improvement in running speed, which for a top runner is a
moderate benefit. But there are likely to be individual differences in the
response to switching to minimalist shoes, so you need to get a physiologist
to test your adaptation via performance in multiple repeated tests (e.g.,
incremental to peak speed). Chronic pain or injury could also be an issue for
some individuals.

On
the other hand, when 25 runners training at least 15 miles per week
were randomized to a parallel-groups 10-wk training study with traditional vsminimalistshoes, the gains were greater
with traditional shoes (8.2% vs 7.0%) [706]. The
authors showed a p value of 0.20, so the difference of -1.2% represents a
likely harmful effect for minimalist shoes when analyzed with magnitude-based
inference. But the huge gains in economy were attributed to "more
consistent training as a result of participation in this study", so
maybe the group training with the minimalist shoes did relatively less
training. I suggest we reserve judgment until there is proper control or
adjustment for training, but meantime I'm making a cautious recommendation
for minimalist shoes, and I declare no industry relationship!

Acknowledgements:
High Performance Sport NZ commissioned a report from WGH. DBP received an
institutional travel grant. Thanks to the reviewer, David Martin, for various
insightful comments and useful additions to this report.